Pronephric duct
Encyclopedia
Development
The development of the pronephric duct is a part of the development of the urinary and reproductive organsDevelopment of the urinary and reproductive organs
The development of the urinary and reproductive organs as a part of the prenatal development, concerns the urinary system and sex organs. The latter is a part of the stages of sexual differentiation....
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In the outer part of the intermediate mesoderm
Intermediate mesoderm
Intermediate mesenchyme or intermediate mesoderm is a type of mesoderm that is located between the paraxial mesoderm and the lateral plate.It develops into the part of the urogenital system * forms of urogenital system...
, immediately under the ectoderm, in the region from the fifth cervical segment to the third thoracic segment, a series of short evaginations from each segment grows dorsally and extends caudally, fusing successively from before backward to form the pronephric duct. This continues to grow caudalward until it opens into the ventral part of the cloaca
Cloaca
In zoological anatomy, a cloaca is the posterior opening that serves as the only such opening for the intestinal, reproductive, and urinary tracts of certain animal species...
; beyond the pronephros it is termed the Wolffian duct
Wolffian duct
The mesonephric duct is a paired organ found in mammals including humans during embryogenesis....
. Thus, the Wolffian duct is what remains of the pronephric duct after the atrophy of the pronephros.